1. Field of the Invention
The present invention relates to a lock structure for bathroom use. In particular, the present invention relates to a bathroom lock that allows unlatching through rotation of an inner handle through a smaller angle.
2. Description of Related Art
FIG. 1 of the drawings illustrates a conventional lock structure for bathroom use, which is disclosed in U.S. patent application Ser. No. 10/173,687. The lock includes an inner rose 10, an outer rose 20, an inner unlatching mechanism 30, and an outer unlatching mechanism 40. The inner unlatching mechanism 30 allows locking by a user in the bathroom and unlocking by turning of an inner handle 11. When in emergency, one may use a tool to turn the outer unlatching mechanism 40 to achieve the unlocking function.
The inner unlatching mechanism 30 includes an inner unlatching rod 31, a fixing member 32, a locking wheel 33, and an elastic element 34, and a follower wheel 35. The inner unlatching rod 31 is pivotally extended through a hole 32 in the fixing member 32 that is fixed to the inner rose 2. The inner unlatching rod 31 is extended through a non-circular hole 333 of the locking wheel 33 to allow joint rotation of the inner unlatching rod 31 and the locking wheel 33. The fixing member 32 further includes an unlatching notch 322 and a locking notch 323 having a depth not equal to that of the unlatching notch 322.
An engaging block 331 projects from a side of the locking wheel 33. Further, the locking wheel 33 includes annularly arranged teeth 332, in a periphery thereof. When the engaging block 331 is engaged in the unlatching notch 322, the locking wheel 33 is biased by the elastic element 34 such that the teeth 332 of the locking wheel 33 disengage from teeth 352 of the follower wheel 35. When the engaging block 331 is engaged in the locking notch 323, the teeth 332 of the locking wheel 33 are engaged in the notch 351 of the follower wheel 35 such that rotation of the outer handle 21 cannot unlatch the lock and that the lock can be unlatched when the inner handle 11 is turned. The elastic element 34 biases the locking wheel 33 such that locking wheel 33 is always in intimate contact with the fixing member 32 and that the engaging block 331 is selectively engaged in one of the unlatching notch 322 and the locking notch 323. Locking can be achieved by turning the inner unlatching rod 31 through 90 degrees to urge the engaging block 331 of the locking wheel 33 to move into the locking groove 323, and the teeth 332 of the locking wheel 33 are engaged with the notch 351 of the follower wheel 35 while moving the outer unlocking mechanism 40 to a state for preventing rotation of the outer spindle 22 and the outer handle 21.
The user may turn the inner handle 11 through 90 degrees for unlatching the lock. However, in actual use, it has been found that sometimes the unlatching procedure is accomplished through forty-five (45) degree rotation of the inner handle 11, which is particularly true when there is a large gap between the door jamb and the end face of the door facing the door jamb. Thus, it is common that the user turns the inner handle 11 through 45 degrees, opens the door, leaves the bathroom, and closes the door again. However, the teeth 332. of the locking wheel 33 have not disengaged from the notch 351 of the follower wheel 35 yet, as the inner handle 11 is only turned through 45 degrees, not 90 degrees. As a result, the bathroom is inadvertently locked. Further, the teeth 332 of the locking wheel 33 and the teeth 352 of the follower wheel 35 are apt to be bent, deformed, and damaged. The depth of the unlatching notch 322 also decreases strength of the fixing member 32. The service life of the bathroom lock is accordingly shortened.
An object of the present invention is to provide a bathroom lock that allows unlatching through rotation of an inner handle through a smaller angle, thereby avoiding unintentional locking of the bathroom resulting from previous unlatching by insufficient rotational movement of the inner handle.
Another object of the present invention is to provide a bathroom lock that has a simplified unlatching mechanism for prolonging the service life of the lock.
A further object of the present invention is to provide a bathroom lock with a fixing member having improved strength for prolonging the service life of the lock.
To achieve the aforementioned objects, the present invention provides a bathroom lock that includes an inner rose, an outer rose, an inner unlatching mechanism, and an outer unlatching mechanism. The inner unlatching mechanism includes an inner unlatching rod, a fixing member, a locking wheel, and a follower plate. The fixing member includes an unlatching groove and a locking groove.
A lock structure for bathroom use in accordance with the present invention comprises an inner rose, an outer rose, an inner unlatching mechanism, and an outer unlatching mechanism. An inner spindle rotatably extends through the inner rose, with an inner handle being attached to the inner spindle to turn therewith. An outer spindle rotatably extends through the outer rose, with an outer handle being attached to the outer spindle to turn therewith. The inner unlatching mechanism comprises an inner unlatching rod, a fixing member, a locking wheel, and a follower wheel.
The inner unlatching rod has a non-circular section and is operably connected to the outer unlatching mechanism. The fixing member is fixed to the inner rose and mounted around the inner unlatching rod. The fixing member includes a first side, a second side, and a central hole through which the inner unlatching rod rotatably extends. An unlatching groove is defined in the first side of the fixing member and tapers to the central through-hole. The unlatching groove is delimited by a truncated conic wall. A locking groove is defined in an end edge of the first side of the fixing member and spaced from the unlatching groove. The locking groove has a depth along a longitudinal direction of the inner unlatching rod not equal to a depth of the unlatching groove along the longitudinal direction of the inner unlatching rod.
The locking wheel is mounted to the inner unlatching rod to turn therewith. The locking wheel includes an engaging block for selectively engaging with one of the unlatching groove and the locking groove of the fixing member. The locking wheel further includes an arcuate drive portion on an outer periphery thereof. The follower wheel is securely mounted around the inner spindle to turn therewith. The follower wheel includes a notch for releasably engaging with the arcuate drive portion of the locking wheel.
When in a locked state, the engaging block of the locking wheel is engaged in the locking groove of the fixing member, and the arcuate drive portion of the locking wheel is engaged in the notch of the follower wheel, with the outer unlatching mechanism being in a state not allowing rotational movement of the outer spindle and the outer handle.
When the inner handle is turned to turn the inner spindle through 40-60 degrees, the engaging block of the locking wheel is moved into the unlatching groove of the fixing member, and the arcuate drive portion of the locking wheel is disengaged from the notch of the follower wheel.
In an embodiment of the invention, the unlatching groove of the fixing member has a width greater than that of the engaging block of the locking wheel, and the unlatching groove of the fixing member has a length greater than that of the engaging block of the locking wheel.
An elastic element is mounted around the inner unlatching rod for biasing the fixing member to press against the inner rose and for biasing the engaging block of the locking wheel to be selectively engaged in one of the unlatching groove and the locking groove of the fixing member. The inner rose includes a hole through which the inner unlatching rod is rotatably extended. A groove is defined in an inner periphery defining the hole of the inner rose. The fixing member further includes a protrusion on the second side thereof. The protrusion of the fixing member is securely engaged in the hole of the inner rose.
The inner unlatching rod has an end extending beyond the inner rose, with an arm being attached to the end of the inner unlatching rod. The locking wheel further includes another arcuate drive portion located on the outer periphery of the locking wheel and diametrically opposed to the arcuate drive portion.
The outer rose has a hole and a pair of plates on both sides of the hole.
The outer unlatching mechanism includes an outer unlatching rod, a stop plate, a locking plate, and a wheel securely mounted to the outer rose to turn therewith and having an engaging groove.
The outer unlatching rod extends through the hole of the outer rose and has a non-circular hole for securely receiving an end of the inner unlatching rod to turn therewith. The outer unlatching rod further has a drive portion located outside a door to which the lock structure is mounted so that the drive portion is drivable by a tool to turn the outer unlatching rod for unlatching.
The stop plate is mounted on the outer unlatching rod and slidable yet not rotatable along a longitudinal axis of the outer unlatching rod. The stop plate is located between the plates of the outer rose and has a protrusion and a hole through which the outer unlatching rod extends.
The locking plate is mounted to the outer unlatching rod to turn therewith. The locking plate has a locking groove having a depth along a longitudinal axis of the outer unlatching rod and an unlatching groove having a depth along the longitudinal axis of the outer unlatching rod not equal to the depth of the locking groove of the locking plate. The protrusion of the stop plate is selectively engaged in one of the locking groove and the unlatching groove of the locking plate.
When in the locked state, the protrusion of the stop plate is engaged in the locking groove of the locking plate, and the stop plate is engaged in the engaging groove of the wheel. When the inner handle is turned for unlatching purposes, the locking plate is so turned that the protrusion of the stop plate is moved into the unlatching groove of the locking plate and that the stop plate is engaged from the engaging groove of the wheel, allowing free rotation of the outer spindle and the outer handle.
The fixing member may further have another locking groove defined in another end edge of the first side of the fixing member that is opposed to the end edge of the first side of the fixing member.